The efficacy and tolerability of vardenafil, a new, oral, selective phosphodiesterase type 5 inhibitor, in patients with erectile dysfunction: the first at-home clinical trial

The Combination of Oolonghomobisflavan B and Diallyl Disulfide Induces Apoptotic Cell Death via 67-kDa Laminin Receptor/Cyclic Guanosine Monophosphate in Acute Myeloid Leukemia Cells

Diallyl disulfide (DADS) is a well-known principal functional component derived from garlic (Allium sativum) that has various health benefits. Previously, we identified a 67-kDa laminin receptor, a receptor for oolong tea polyphenol oolonghomobisflavan B (OHBFB). However, its molecular mechanisms still remain to be elucidated. Here, we show that DADS synergistically enhanced the effect of the oolong tea polyphenol oolonghomobisflavan B (OHBFB), which induces apoptosis in acute myeloid leukemia (AML) cancer cells without affecting normal human peripheral blood mononuclear cells (PBMCs). The underlying mechanism of OHBFB-induced anti-AML effects involves the upregulation of the 67-kDa laminin receptor/endothelial nitric oxide synthase/cyclic guanosine monophosphate (cGMP)/protein kinase c delta (PKCδ)/acid sphingomyelinase (ASM)/cleaved caspase-3 signaling pathway. In conclusion, we show that the combination of OHBFB and DADS synergistically induced apoptotic cell death in AML cells through activation of 67LR/cGMP/PKCδ/ASM signaling pathway. Moreover, in this mechanism, we demonstrate DADS may reduce the enzyme activity of phosphodiesterase, which is a negative regulator of cGMP that potentiates OHBFB-induced AML apoptotic cell death without affecting normal PBMCs.

Platelet-rich plasma intracavernosal injections for the treatment of primary organic erectile dysfunction: a systematic review and meta-analysis of contemporary controlled studies

We aim to summarize the latest evidence on platelet-rich plasma (PRP) intracavernosal injections efficacy in men affected by primary organic erectile dysfunction (ED). We reviewed the literature for randomized controlled trials (RCTs) or prospective and retrospective comparative studies evaluating PRP alone or in combination for ED treatment. A comprehensive search in PubMed, Scopus, Web of Science, and ClinicalTrials.gov was performed for English language full-text articles or conference abstracts. A qualitative and quantitative data synthesis was provided. Overall, seven records were included: three RCTs evaluated PRP vs. placebo, one study separately tested PRP and low-intensity shock wave therapy (Li-SWT), three studies compared Li-SWT or low-intensity pulsed ultrasound alone with their combination with PRP. Of 641 included patients, 320 received PRP. Despite the heterogeneity among inclusion criteria, dose and protocol of PRP administration, and outcomes measured, most studies independently reported better sexual outcomes in patients who received PRP, without significant severe side effects. In meta-analysis, where only placebo-controlled studies were included, patients treated with PRP showed higher International Index of Erectile Function (erectile function domain) score compared to patients who received placebo: pooled mean difference (95% Confidence Interval) of 2.99 (1.86, 4.13) after 1 month (209 patients) vs. 2.85 (1.61, 4.09) after 3 months (204 patients) vs. 3.21 (1.82, 4.60) after 6 months (199 patients) of follow-up. In men affected by primary organic ED, PRP intracavernosal injections demonstrated an objective improvement or at least a tendency in erectile function recovery. Patient numbers, and the short-term follow-up may limit the generalizability of these observations. High quality, large-scale, and standardized controlled trials are needed before recommending its definitive use in clinical practice.

The anti-cancer effect of epigallocatechin-3-O-gallate against multiple myeloma cells is potentiated by 5,7-dimethoxyflavone

(-)-Epigallocatechin-3-O-gallate (EGCG) is one of the major components of green tea polyphenol. Previous studies have shown that EGCG induces cancer-specific cell death in vitro and in vivo without causing severe side effects. However, the anti-cancer effect of EGCG alone is limited. 5,7-dimethoxyflavone (5,7-DMF), one of the principal functional components of black ginger (Kaempferia parviflora), also exerts anti-cancer effects. Here, we show that 5,7-DMF synergistically enhances the anti-cancer effect of EGCG in multiple myeloma cells by potentiating EGCG-induced intracellular cyclic guanosine monophosphate (cGMP) production. Moreover, the combination of EGCG and 5,7-DMF induces apoptotic cell death in multiple myeloma cells, and this is accompanied by activation of the cGMP/acid sphingomyelinase (ASM)/cleaved caspase-3 pathway. In conclusion, we have shown that 5,7-DMF enhances the anti-cancer effect of EGCG by upregulating cGMP in multiple myeloma cells.

Vardenafil alleviates cigarette smoke-induced chronic obstructive pulmonary disease by activating autophagy via the AMPK/mTOR signalling pathway: an in vitro and in vivo study

Chronic obstructive pulmonary disease (COPD) has always attracted global attention with its high prevalence, incidence rate, and mortality. Exposure to cigarette smoke is one of main causes of COPD. Therefore, it is still necessary to study its pathogenesis and find new therapeutic strategies for early COPD prevention and treatment. Vardenafil, a type 5 phosphodiesterase (PDE5) inhibitor, is known to have an efficient therapy in some cardiovascular, pulmonary, and vascular diseases, which is an important mechanism for COPD. However, it still loss relevant research on whether vardenafil is effective in COPD and its mechanism. In this study, the cigarette smoke inhalation was performed to establish cigarette smoke-induced COPD model using C57BL/6 mice and 16HBE cells were treated with cigarette smoke extract (CSE). Mice were treated with vardenafil for 30 d. Then condition of lung injury was evaluated using histological analysis. The content of cytokines and the number of inflammatory cells in lung tissues or bronchoalveolar lavage fluid were measured. Additionally, western blot analysis was employed to evaluate the activation of adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK)/mechanistic target of rapamycin (mTOR)-mediated autophagy in vitro. The results showed that vardenafil abolished CSE's effect by activating autophagy via the AMPK/mTOR signalling pathway in vitro. Vardenafil attenuated cigarette smoke-induced lung injury and inflammation response by activating autophagy via the AMPK/mTOR signalling pathway in vivo. These results provide valuable insights into the molecular mechanisms underlying vardenafil's beneficial effects in cigarette smoke-induced COPD treatment. In conclusion, vardenafil alleviates cigarette smoke-induced experimental COPD by activating autophagy via the AMPK/mTOR signalling pathway.

Long-term effects of combination treatment comprising low-intensity extracorporeal shockwave therapy and tadalafil for patients with erectile dysfunction: a retrospective study

This study retrospectively examined the effects of low-intensity extracorporeal shockwave therapy and tadalafil on erectile dysfunction patients. 116 patients got low-intensity extracorporeal shockwave therapy twice weekly for 3 weeks, 5 mg of tadalafil daily for 3 weeks, and adjuvant therapy for 6 months. Group A (1 year), Group B (2 years), Group C (3 years), and Group D (4+ years) were treated patients' follow-up groups. The patients' International Index of Erectile Function-5 (IIEF-5) scores were gathered at the start of treatment via face-to-face interviews and at the end of follow-ups by telephone conversations. IIEF-5 scores and the minimal clinically significant differences were the main outcomes. Mean follow-up length, age, and IIEF-5 scores of the patients were 2 ± 1.16 years, 47.34 ± 12.65 years, and 12.09 ± 3.66 points, respectively. Compared to baseline, treatment increased the median IIEF-5 scores of patients in groups A, B, C, and D by 7 [3-12], 6 [0-8], 7 [1-9], and 6.5 [2.5-10] points, respectively (p = 0.001). 71%, 63%, 65.8%, and 65% of treated patients in groups A, B, C, and D met the minimal clinically significant differences criteria (n = 77). Mild disease patients were 9.14 times more likely to respond to treatment than severe illness patients (OR, 9.14; 95% CI, 1.28-65.46; P = 0.02). Low-intensity extracorporeal shockwave therapy and 5 mg of tadalafil can treat erectile dysfunction for up to 4 years with sustained outcomes. This treatment is optimal for mild illnesses.

Beyond Erectile Dysfunction: cGMP-Specific Phosphodiesterase 5 Inhibitors for Other Clinical Disorders

Cyclic guanosine monophosphate (cGMP), an important intracellular second messenger, mediates cellular functional responses in all vital organs. Phosphodiesterase 5 (PDE5) is one of the 11 members of the cyclic nucleotide phosphodiesterase (PDE) family that specifically targets cGMP generated by nitric oxide-driven activation of the soluble guanylyl cyclase. PDE5 inhibitors, including sildenafil and tadalafil, are widely used for the treatment of erectile dysfunction, pulmonary arterial hypertension, and certain urological disorders. Preclinical studies have shown promising effects of PDE5 inhibitors in the treatment of myocardial infarction, cardiac hypertrophy, heart failure, cancer and anticancer-drug-associated cardiotoxicity, diabetes, Duchenne muscular dystrophy, Alzheimer's disease, and other aging-related conditions. Many clinical trials with PDE5 inhibitors have focused on the potential cardiovascular, anticancer, and neurological benefits. In this review, we provide an overview of the current state of knowledge on PDE5 inhibitors and their potential therapeutic indications for various clinical disorders beyond erectile dysfunction.

Phosphodiesterase 5 Inhibitor Potentiates Epigallocatechin 3-O-Gallate-Induced Apoptotic Cell Death via Activation of the cGMP Signaling Pathway in Caco-2 Cells

Epigallocatechin 3-O-gallate (EGCG) is a predominant component in green tea with various health benefits. The 67 kDa laminin receptor (67LR) is a nonintegrin cell surface receptor that is overexpressed in various types of cancer; 67LR was identified a cell surface EGCG target that plays a pivotal role in tumor growth, metastasis, and resistance to chemotherapy. However, the plasma concentration of EGCG is limited, and its molecular mechanisms remain unelucidated in colon cancer. In this study, we found that the phosphodiesterase 5 (PDE5) inhibitor, vardenafil (VDN), potentiates EGCG-induced apoptotic cell death in colon cancer cells. The combination of EGCG and VDN induced apoptosis via activation of the endothelial nitric oxide synthase/cyclic guanosine monophosphate/protein kinase Cδ signaling pathway. In conclusion, the PDE5 inhibitor, VDN, may reduce the intracellular PDE5 enzyme activity that potentiates EGCG-induced apoptotic cell death in Caco-2 cells. These results suggest that PDE5 inhibitors can be used to elevate cGMP levels to induce 67LR-mediated, cancer-specific cell death. Therefore, EGCG may be employed as a therapeutic candidate for colon cancer.

Effects of bariatric surgery on testosterone level and sexual function in men with obesity: A retrospective study

INTRODUCTION

Bariatric surgeries induce well-documented weight loss and resolve obesity comorbidities. Sexual function is one of the aspects of life quality and may benefit from surgery. Few studies have revealed the impact of bariatric surgeries on sexual function in Chinese men with obesity.

METHODS

This is a retrospective cohort study of patients undergoing bariatric surgery [laparoscopic sleeve gastrectomy (LSG) or laparoscopic Roux-en-Y gastric bypass (LRYGB)]. Data were collected between September 2017 and February 2022. The International Index of Erectile Function (IIEF) questionnaire was used to evaluate erectile function, intercourse satisfaction, orgasmic function, sexual desire, and overall satisfaction. Sex hormones and other blood tests were evaluated before and at least 1 year after the surgery.

RESULTS

Fifty-nine Chinese male patients completed the IIEF questionnaire. The multivariate logistic regression analysis revealed that body mass index (BMI) was the single independent risk factor of the severity of erectile dysfunction (ED). Preoperative testosterone levels had negative correlations with BMI and waist circumference. Thirty-seven patients completed the postoperative questionnaire with a mean follow-up of 23.2 months.

CONCLUSION

BMI and waist circumference were negatively correlated with testosterone levels. BMI was an independent risk factor for the severity of ED. LSG and LRYGB led to positive and sustained improvement in sexual function of men with obesity. The two procedures had a comparable effect, more subjects being needed. Sex hormone levels also could be reversible. However, more weight loss did not predict a positive change in sexual function. A greater BMI loss might predict a greater increase in testosterone.

Activation of the iNOS/NO/cGMP pathway by Revactin® in human corporal smooth muscle cells

Background

The combination of the nutraceuticals, Paullinia cupana, ginger rhizome, muira puama, and the amino acid L-citrulline (COMP-4) has been shown to stimulate the production of inducible nitric oxide synthase (iNOS), nitric oxide (NO), and cGMP in rat corpora cavernosa smooth muscle cells (CSMC). When administered to middle-aged rats, long-term treatment with COMP-4 resulted in both an increase in the number of CSMC and an improvement in erectile function. We, therefore, aimed to determine whether a commercial formulation of COMP-4, Revactin^®, could have a similar stimulatory effect on human CSMC.

Methods

Primary human CSMC cultures (HCSMC) were grown and incubated with Revactin® for up to 24 hours. cGMP generation and nitrite formation were determined by ELISA and Griess reaction, respectively. IBMX (1 mM), sildenafil (0.4 mM), and L-NIL (4 µM) were utilized as modulators of the NO-cGMP pathway. iNOS, endothelial NOS (eNOS), and neuronal NOS (nNOS) expressions were determined by Western blot.

Results

Revactin^® up-regulated both nitrite formation and cGMP expression, achieving the highest expression at 24 hours in the HCSMC. These effects were completely blocked by L-NIL. Revactin^® up-regulated iNOS expression, but not that of eNOS or nNOS.

Conclusions

The results presented in this study confirmed that Revactin^® activated the iNOS-NO-cGMP pathway intracellularly in HCSMC. It still needs to be determined whether the upregulation of this pathway would be an effective approach for counteracting the fibrosis and apoptosis of the corporal smooth muscle cells associated with aging.

A validated LC-MS/MS assay for the quantification of phosphodiesterase-5 inhibitors in human plasma

Phosphodiesterase inhibitors (PDE5i) are considered the first line therapy for erectile dysfunction. All PDE5i available on the market are structurally related; their main differences relate to their pharmacokinetic parameters. For these treatments to be effective and safe, it is necessary that these drugs are in the appropriate doses and that they reach adequate concentrations in the plasma. For this purpose, it is essential to perform therapeutic monitoring using bioanalytical methods. In this way, the present work aimed to develop and validate a new bioanalytical method, based on LC-MS/MS, for the simultaneous quantification of six commercially available PDE5i (avanafil, lodenafil, sildenafil, tadalafil, udenafil, and vardenafil). For this purpose, the human plasma was extracted with diethyl ether and sulfaquinoxaline was established as an internal standard. Separation was achieved using an Xbridge C18 column at 40 °C as the stationary phase, using water and acetonitrile as the mobile phase (both with formic acid and ammonium formate) in gradient mode. The method was validated according to the current guidelines and was found to be selective, linear (from 1 to 200 ng.mL^-1 for all drugs except for tadalafil which is from 5 to 200 ng.mL^-1), precise, accurate, and free of residual and matrix effects. The drugs were considered stable in plasma and in solution under different conditions. The method was applied to volunteerssamples, demonstrating that the method can be used routinely and may be useful in future studies on pharmacokinetics and therapeutic monitoring.

Vardenafil in the Treatment of Male Erectile Dysfunction: A Systematic Review and Meta-Analysis

INTRODUCTION

We carried out this systemic review and meta-analysis of relevant randomized controlled trials to determine different dosage regimens of vardenafil in the treatment of male erectile dysfunction (ED).

METHODS

Using appropriate keywords, we searched PubMed, the Cochrane Library, and Embase for relevant literature before March 2020. We evaluated odds ratio (OR), weighted mean difference (WMD), and 95% confidence interval (95% CI) to assess the results of each study.

RESULTS

We included 14 studies with a total of 3221 patients. Compared with the placebo, vardenafil significantly increased International Erectile Function Index (IIEF) overall satisfaction (WMD 3.37, 95% CI 2.02-4.71), IIEF-erectile function (WMD 7.93, 95% CI 6.00-9.85), IIEF sexual desire (WMD 0.79, 95% CI 0.24-1.35), IIEF intercourse satisfaction (WMD 5.24, 95% CI 3.35-7.13), IIEF orgasmic function (WMD 3.81, 95% CI 2.26-5.35), Sexual Encounter Profile (SEP) Q2 (WMD 26.36, 95% CI 22.95-29.77), and SEP Q3 (WMD 35.18, 95% CI 31.89-38.48).

CONCLUSIONS

Vardenafil demonstrated significant efficacy in the treatment of ED, but the optimal dose and course of vardenafil remain to be established.

Human tissue kallikrein-1 protects against the development of erectile dysfunction in a rat model of hyperhomocysteinemia

The aim of this study was to investigate the mechanism by which a diet inducing high hyperhomocysteinemia (HHcy) leads to the deterioration of erectile function in rats and whether this is inhibited by expression of the human tissue kallikrein-1 (hKLK1) gene. We established a rat model of HHcy by feeding methionine (Met)-rich diets to male Sprague-Dawley (SD) rats. Male wild-type SD rats (WTRs) and transgenic rats harboring the hKLK1 gene (TGRs) were fed a normal diet until 10 weeks of age. Then, 30 WTRs were randomly divided into three groups as follows: the control (n = 10) group, the low-dose (4% Met, n = 10) group, and the high-dose (7% Met, n = 10) group. Another 10 age-matched TGRs were fed the high-dose diet and designated as the TGR+7% Met group. After 30 days, in all four groups, erectile function was measured and penile tissues were harvested to determine oxidative stress, endothelial cell content, and penis fibrosis. Compared with the 7% Met group, the TGR+7% Met group showed diminished HHcy-induced erectile dysfunction (ED), indicating the improvement caused by hKLK1. Regarding corpus cavernosum endothelial cells, hKLK1 preserved endothelial cell-cell junctions and endothelial cell content, and activated protein kinase B/endothelial nitric oxide synthase (Akt/eNOS) signaling. Fibrosis assessment indicated that hKLK1 preserved normal penis structure by inhibiting apoptosis in the corpus cavernosum smooth muscle cells. Taken together, these findings showed that oxidative stress, impaired corpus cavernosum endothelial cells, and severe penis fibrosis were involved in the induction of ED by HHcy in rats, whereas hKLK1 preserved erectile function by inhibiting these pathophysiological changes.

Role of application of tadalafil 5 mg once-daily (≥6 months) in men with erectile dysfunction from six randomized controlled trials

This meta-analysis was performed to assess the efficacy and safety of taking tadalafil 5 mg once-daily for at least 6 months in the treatment of erectile dysfunction (ED). Based on databases: MEDLINE, EMBASE and Cochrane Controlled Trials Register, this analysis was performed to collect randomized controlled trials (RCTs) of tadalafil 5mg once-daily in treating ED over 6 months. Reviewers also investigated the references of each literature. The meta-analysis covered a total of 1,596 patients in six RCTs. The tadalafil group performed a better effect in terms of the international index of erectile function-erectile function (IIEF) domain (P=0.005) for the treatment of ED compared with the placebo group. Safety assessments including discontinuations due to adverse events (AEs) (P=0.31) and treatment-emergent AEs (P=0.06) indicated that the tadalafil group had a better tolerate. The analysis elucidates that the dose of 5 mg per day of tadalafil showed a good effect after the treatment of at least 6 months relative to the control group with fewer side effects.

Type 5 phosphodiesterase (PDE5) and the vascular tree: From embryogenesis to aging and disease

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Vascular development depends on the timely differentiation of endothelial and smooth muscle cells.

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Vascular aging and vascular disease are influenced by endothelial and vascular smooth muscle cell compartments.

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A survey of the literature on the role of PDE5 in vascular development, aging and disease is reported.

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The role of PDE5 on vascular development, aging and disease needs to be further investigated by its genetic ablation.

Vascular tree development depends on the timely differentiation of endothelial and vascular smooth muscle cells. These latter are key players in the formation of the vascular scaffold that offers resistance to the blood flow. This review aims at providing an overview on the role of PDE5, the cGMP-specific phosphodiesterase that historically attracted much attention for its involvement in male impotence, in the regulation of vascular smooth muscle cell function. The overall goal is to underscore the importance of PDE5 expression and activity in this cell type in the context of the organs where its function has been extensively studied.

Placebo Responses Among Men With Erectile Dysfunction Enrolled in Phosphodiesterase 5 Inhibitor Trials: A Systematic Review and Meta-analysis

IMPORTANCE

Placebo responses in the treatment of erectile dysfunction (ED) are poorly described in the literature to date.

OBJECTIVE

To quantify the association of placebo with ED outcomes among men enrolled in placebo-controlled, phosphodiesterase 5 inhibitor (PDE5I) trials.

DATA SOURCES

For this systematic review and meta-analysis, a database search was conducted to identify double-blind, placebo-controlled studies using PDE5Is for the treatment of ED published from January 1, 1998, to December 31, 2018, within MEDLINE, Embase, Cochrane Library, and Web of Science. Only articles published in the English language were included.

STUDY SELECTION

Double-blind, placebo-controlled randomized clinical trials of PDE5Is for ED were included. Studies were excluded if they did not provide distribution measures for statistical analysis. Study selection review assessments were conducted by 2 independent investigators. A total of 2215 studies were identified from the database search, and after review, 63 studies that included 12 564 men were analyzed.

DATA EXTRACTION AND SYNTHESIS

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were followed in abstracting data and assessing validity. Data were extracted from published reports by 2 independent reviewers. Quality assessment was performed using the Jadad scale. Data were pooled using a random-effects model.

MAIN OUTCOMES AND MEASURES

The main outcome was improvement in the erectile function domain of the International Index of Erectile Function questionnaire in the placebo arm of the included studies. Effect size was reported as bias-corrected standardized mean difference (Hedges g). The hypothesis was formulated before data extraction.

RESULTS

A total of 63 studies that included 12 564 men (mean [SD] age, 55 [7] years; age range, 36-68 years) were included. Erectile function was significantly improved among participants in the placebo arm, with a small to moderate effect size (Hedges g [SE], 0.35 [0.03]; P < .001). Placebo effect size was larger among participants with ED associated with posttraumatic stress disorder (Hedges g [SE], 0.78 [0.32]; P = .02) compared with the overall analysis. No significant difference was found between placebo and PDE5Is for ED after prostate surgery or radiotherapy (Hedges g [SE], 0.30 [0.17]; P = .08).

CONCLUSIONS AND RELEVANCE

In this study, placebo was associated with improvement of ED, especially among men with ED-related posttraumatic stress disorder. No difference was found between placebo and PDE5I among men treated for ED after prostate surgery.

Ocular side effects of Levitra® (vardenafil) - results of a double-blind crossover study in healthy male subjects

Purpose

To determine ocular side effects of vardenafil with special regard to color vision and retinal function.

Methods

This was a single center, randomized, double-blind, placebo-controlled, twofold crossover study with an administration of a single oral dose of two 20 mg tablets of BAY 38–9456 (vardenafil hydrochloride) or corresponding placebo in 24 healthy male subjects. Ocular investigations included Farnsworth–Munsell D100 color vision test, electroretinogram, and basic ophthalmological examinations like visual acuity, visual field, and slit-lamp of anterior segment and fundus.

Results

Compared to placebo, administration of vardenafil hydrochloride lead to a temporary significant increase of Farnsworth–Munsell D100 total error score after 1 and 6 hours as well as in error lines 3 and 4 after 1 hour. Twenty-four hours after administration there was no significant alteration of total error score or of any error line. While latency of electroretinogram b-wave remained unaffected, amplitudes showed a significant decrease compared to placebo 1 hour following administration. While other ocular examinations did not reveal any differences in general some mild to moderate but no serious adverse events have been reported.

Conclusion

Despite temporary changes in retinal function our study reports good tolerability of vardenafil in regard to ocular side effects.

Aberrant baseline brain activity in psychogenic erectile dysfunction patients: a resting state fMRI study

Recent neuroimaging studies have elucidated many interesting and promising findings on sexuality regarding the neural underpinnings of both normal and abnormal sexual processes. Psychogenic erectile dysfunction (pED) consists of a major part of male sexual dysfunction in China, but the understanding of the central mechanism of pED is still in its infancy. It is commonly appreciated that pED is a functional disorder, which can be attributed predominantly or exclusively to psychological factors, such as anxiety, depression, loss of self-esteem, and psychosocial stresses. Most previous studies probed the central response in the brain of pED patients using sexual-related stimuli. However, little concern has been given to a more fundamental issue whether the baseline brain activity is altered in pED or not. With rs-fMRI data, the current study aimed to explain the central mechanism behind pED by investigating the alterations in baseline brain activity in patients with pED, as indexed by the amplitude of low-frequency (0.01-0.08 Hz) fluctuation (ALFF). After the psychological screening and urological examination procedure, 26 pED patients and 26 healthy matched controls were enrolled. Our results explicated significantly lower baseline brain activity in the right anterior insula and right orbitofrontal cortex for pED patients (multiple comparison corrected). Additionally, the voxel-wise correlation analysis showed that ALFF of the right anterior insula was correlated with the outcomes of erectile function (multiple comparison corrected). Our results implied there was impaired cognitive and motivational processing of sexual stimuli in pED patients. Our current findings may shed light on the neural pathology underlying pED. We hope that our study has provided a new angle looking into pED research by investigating resting state brain activity. Furthermore, we suggest that the current study may put forward a more subtle conception of insular influence on pED, which may help foster new specific, mechanistic insights.

Local condiments from fermented tropical legume seeds modulate activities of critical enzymes relevant to cardiovascular diseases and endothelial function

Investigation into modulatory effects of local condiments produced from fermented legume (African locust bean and soybean) seeds on activities of enzymes relevant to endothelial function and cardiovascular disease (arginase, phosphodiesterase-5, acetylcholinesterase, and, ecto 5'-nucleotidase) in vitro was the focus of this study. The condiments were prepared according to traditional methods of fermentation. Thereafter, modulatory effects of aqueous extracts from the condiments on activities of the enzymes were subsequently carried out. Results showed the extracts significantly inhibited activities of arginase, phosphodiesterase-5 and acetylcholinesterase, while the activity of ecto 5'-nucleotidase was stimulated at sample concentrations tested. Thus, the observed enzyme modulatory properties exhibited by the condiments could be novel mechanisms to support their use as functional foods and nutraceuticals for the management of cardiovascular disease and associated endothelial dysfunction.

Sexual habits of men with ED who take phosphodiesterase 5 inhibitors: a survey conducted in 7 countries

INTRODUCTION

Western cultural perceptions that favour spontaneous sex may create unrealistic expectations for erectile dysfunction (ED) treatment. Little is known about how users of phosphodiesterase type 5 inhibitors (PDE5Is) plan sexual activity and timing of their preactivity PDE5I ingestion. Because various PDE5Is vary in their duration of action and dosage regimen, this may be an important consideration in selecting the optimal agent for the ED patient.

AIM

To better understand the sexual habits of PDE5I users.

METHODS

Men from 7 countries (Brazil, China, Italy, Japan, Russia, Taiwan, Turkey) were screened online for age, self-reported comorbidities and ED medication use in the prior 3 months. After screening, eligible participants were asked to complete a 7-question, self-administered online survey containing questions regarding sexual habits and behaviours.

MAIN OUTCOME MEASURES

Survey questions focused primarily on advanced planning of sexual intercourse and timing of PDE5I ingestion but also addressed the frequency of sexual intercourse and ED medication use.

RESULTS

Of the 1458 respondents (response rate: 48%; median age: 48 years [interquartile range (IQR), 44-55]), 83% always/sometimes planned a specific time for intercourse in advance; 72% planned a specific time for sexual intercourse up to several hours in advance. Of respondents who planned in advance, more than half planned specific days of the week (55%) and times of the day (60%) for sexual intercourse. The time to sexual intercourse after dosing was ≤1 hour for 70% and ≤4 hours for 96% of men. The median frequency of sexual intercourse was 6 times/month (IQR, 4-10), with ED medication taken a median of 5 times/month (IQR, 3-8).

CONCLUSIONS

Sexual activity is usually planned by ED medication users several hours in advance, and the vast majority are attempting activity within a short time after ingestion of the agent. These data should aid clinicians in the selection of the optimal PDE5I.

Sexual Dysfunction: Behavioral, Medical, and Surgical Treatment

Sexual dysfunction affects both men and women and is responsible for 1 in 5 visits to urologist and/or gynecologists. It is important that treating providers use a logical and methodical approach to the diagnosis and treatment of this disorder. Behavioral therapy, coupled with oral medications, are very successful in treating erectile dysfunction. Complex and invasive therapies are used for more severe cases of sexual dysfunction and are best deployed by specialists.

Hydrogen sulphide donors selectively potentiate a green tea polyphenol EGCG-induced apoptosis of multiple myeloma cells

Hydrogen sulphide (H₂S) is a colourless gas with the odour of rotten eggs and has recently been recognized as a signal mediator in physiological activities related with the regulation of homeostasis, the vascular system and the inflammatory system. Here we show that H₂S donors, including sodium hydrogen sulphide (NaHS), GYY 4137 and diallyltrisulfide (DATS), synergistically enhanced the anti-cancer effect of a green tea polyphenol (−)-epigallocatechin-3-O-gallate (EGCG) against multiple myeloma cells without affecting normal cells. NaHS significantly potentiated the anti-cancer effect of EGCG and prolonged survival in a mouse xenograft model. In this mechanism, H₂S enhanced apoptotic cell death through cyclic guanosine monophosphate (cGMP)/acid sphingomyelinase pathway induced by EGCG. Moreover, NaHS reduced the enzyme activity of cyclic nucleotide phosphodiesterase that is known as cGMP negative regulator. In conclusion, we identified H₂S as a gasotransmitter that potentiates EGCG-induced cancer cell death.

Aberrant Insula-Centered Functional Connectivity in Psychogenic Erectile Dysfunction Patients: A Resting-State fMRI Study

Most previous studies exploring the neural mechanism of psychogenic erectile dysfunction (pED) focused on brain activity under tasks. We suggest that the resting brain activity is equally important in pED studies, in that the patterns of spontaneous neural activities is independent of modalities of sensory input, therefore providing substantial information regarding the central mechanism of pED. Our previous study reported the altered baseline activity in right anterior insula (aINS) in pED patients. Also, the insula is a pivotal region in sexual behavior, which is suggested to be able to directly mediate erection. Therefore, the current study employed resting-state fMRI to examine alterations in functional connectivity (FC) of the aINS comparing pED patients with matched control subjects. After rigorous participant inclusion procedure, 27 pED patients and 27 healthy male controls were enrolled. Our results elucidated the disrupted homogeneity within the right aINS and aberrant connection patterns between the right aINS and the right dorsolateral prefrontal cortex (dlPFC), as well as the right aINS and the right temporoparietal junction (TPJ) respectively in pED group, as compared with the healthy controls. In conclusion, our results demonstrated the aberrant insula-centered FC in pED, which may be related to the abnormal representation of internal bodily state or needs in pED patients and thus further affect the inhibitory control in the sexual context. We hope that these findings may shed new light on the understanding of the central mechanism of pED.

Review: PDE-5 inhibitors — a summary

The orally administered PDE-5 inhibitors have become first-line treatment for erectile dysfunction. Although the three currently available PDE-5 inhibitors have shown similar efficacy, tadalafil has a much longer half-life than sildenafil or vardenafil, and the pharmacokinetic profile of tadalafil is not affected by food. However, there is a more immediate response to dosing with sildenafil and vardenafil than tadalafil. As with all drugs, there will be individual variations in response and the physician's skill is in finding the right drug for the right patient.

Review: Modern treatment of erectile dysfunction

Within the last two decades, major advances have been made in the development of effective treatments for erectile dysfunction. Oral therapy is now established as the mainstay of treatment and new treatments continue to emerge following the launch of sildenafil in 1998. We review here modern treatment strategies for erectile dysfunction.

Erectile dysfunction in patients with diabetes mellitus — advances in treatment with phosphodiesterase type 5 inhibitors

Erectile dysfunction (ED) is a common complication of diabetes mellitus. In four independent, 12-week, randomised, placebo-controlled clinical trials that evaluated the pro-erectile properties of the selective phosphodiesterase type 5 (PDE-5) inhibitors, sildenafil (Viagra) (25—100 mg), tadalafil (10 and 20 mg) and vardenafil (10 and 20 mg) in men with ED secondary to diabetes mellitus, all the active drugs were significantly superior to placebo. In this difficult-to-treat population, the greatest difference from placebo for the overall responder rate of diabetic men reporting improved erections occurred with vardenafil 20 mg (72% vs. 13% for placebo).

All the PDE-5 inhibitors were generally well tolerated. There were fewer reports of visual disturbance with vardenafil or tadalafil than with sildenafil, which may be due to their greater selectivity for PDE-5 inhibition and less cross-reactivity with retinal PDE-6 inhibition.

The studies suggest there may be significant differences between the three drugs. However, only head-to-head studies will determine true differences in both efficacy and side effect profile.

The devil is in the details: an analysis of the subtleties between phosphodiesterase inhibitors for erectile dysfunction

Erectile dysfunction (ED) is a common sexual disorder with numerous etiologies involving multiple organ systems that leads to significant distress and decreased quality of life for the affected men. Fortunately, there are several modalities and interventions for treating ED. Oral medications, intra-urethral compounds, intracorporeal injections, vacuum-assist devices and surgically implanted prostheses are all part of the treatment algorithm. One of the first-lines and certainly the most widely used options for treating ED is the family of oral phosphodiesterase type 5 inhibitors (PDE5I). The introduction of these medications in the late 1990s revolutionized the field of sexual medicine. Currently there are no guidelines and minimal literature to help providers choose among drugs in this class. This review will address differences in efficacy and side effects between various members of the oral selective phosphodiesterase-5 inhibitor class of drugs.

Patient Insight and Treatment Expectations in Erectile Dysfunction

In the literature, a strong preference towards pharmacological management with oral phosphodiesterase type 5 (PDE5) inhibitors has been demonstrated in men with erectile dysfunction (ED) versus other methods. However, following pharmacological management, a large proportion of men with ED discontinue treatment prematurely. Therefore, a better understanding of the expectations from, and demands on modern ED management from both the patients and their partners is needed in order to identify factors that may improve outcomes, patient adherence, and patient satisfaction with therapy. Thus, we will present new findings on patient and partner satisfaction and preferences, and discuss how the current pharmacological armamentarium can answer these needs.

Molecular and functional characterization of Kv 7 channels in penile arteries and corpus cavernosum of healthy and metabolic syndrome rats

BACKGROUND AND PURPOSE

KCNQ-encoded voltage-dependent potassium channels (Kv 7) are involved in the regulation of vascular tone. In this study we evaluated the influence of Kv 7 channel activation on smooth muscle relaxation in rat penile arteries and corpus cavernosum from normal and spontaneously hypertensive, heart failure-prone (SHHF) rats - a rat model of human metabolic syndrome.

EXPERIMENTAL APPROACH

Quantitative PCR and immunohistochemistry were used to determine the expression of KCNQ isoforms in penile tissue. Isometric tension was measured in intracavernous arterial rings and corpus cavernosum strips isolated from normal and SHHF rats.

KEY RESULTS

Transcripts for KCNQ3, KCNQ4 and KCNQ5 were detected in penile arteries and corpus cavernosum. KCNQ1 was only found in corpus cavernosum. Immunofluorescence signals to Kv 7.4 and Kv 7.5 were found in penile arteries, penile veins and corpus cavernosum. The Kv 7.2-7.5 activators, ML213 and BMS204352, relaxed pre-contracted penile arteries and corpus cavernosum independently of nitric oxide synthase or endothelium-derived hyperpolarization. Relaxations to sildenafil, a PDE5 inhibitor, and sodium nitroprusside (SNP), an nitric oxide donor, were reduced by blocking Kv 7 channels with linopirdine in penile arteries and corpus cavernosum. In SHHF rat penile arteries and corpus cavernosum, relaxations to ML213 and BMS204352 were attenuated, and the blocking effect of linopirdine on sildenafil-induced and SNP-induced relaxations reduced. KCNQ3, KCNQ4 and KCNQ5 were down-regulated, and KCNQ1 was up-regulated in corpus cavernosum from SHHF rats. KCNQ1-5 transcripts remained unchanged in penile arteries from SHHF rats.

CONCLUSIONS AND IMPLICATIONS

These data suggest that Kv 7 channels play a role in erectile function and contribute to the pathophysiology of erectile dysfunction, an early indicator of cardiovascular disease.

Erectile dysfunction drugs and oxidative stress in the liver of male rats

Erectile dysfunction (ED) affected the lives of more than 300 million men worldwide. Erectile dysfunction drugs (EDD), known as phosphodiesterase inhibitors (PDEIs), have been used for treatment of ED. It has been shown that oxidative stress plays an important role in the progression of erectile dysfunction. Oxidative stress can be alleviated or decreased by antioxidant enzymes. Therefore, the present study aims at investigating the changes in the activity of antioxidant enzymes such as superoxide dismutase, catalase, and glutathione reductase as well as protein expression of glutathione peroxidase and glutathione S-transferase after treatment of male rats with a daily dose of sildenafil (1.48 mg/kg), tadalafil (0.285 mg/kg) and vardenafil (0.285 mg/kg) for three weeks. In addition, levels of reduced glutathione and malondialdyhyde (MDA) were assayed. The present study showed that sildenafil, vardenafil, and tadalafil treatments significantly decreased the levels of glutathione, MDA and the activity of glutathione reductase. In addition, vardenafil and sildenafil increased the activity of superoxide dismutase and catalase. Interestingly, western immunoblotting data showed that vardenafil induced the activity of glutathione peroxidase (GP_X) and its protein expression, whereas tadalafil and sildenafil inhibited such enzyme activity and its protein expression. In addition, the protein expression of GST π isozyme was markedly reduced after treatment of rats with sildenafil. It is concluded that ED drugs induced the activities of both SOD and catalase which consequently decreased MDA level. Therefore, decrement in MDA levels could increase nitric oxide–cGMP level which in turn promotes the erection mechanism.

Designed angiopoietin-1 variant, COMP-angiopoietin-1, rescues erectile function through healthy cavernous angiogenesis in a hypercholesterolemic mouse

Despite the advent of oral phosphodiesterase-5 inhibitors, curative treatment for erectile dysfunction (ED) remains unavailable. Recently, the link between ED and cardiovascular disease was unveiled and the main etiology of ED was found to be vasculogenic. Therefore, neovascularization is a promising strategy for curing ED. Angiopoietin-1 (Ang1) is an angiogenic growth factor that promotes the generation of stable and functional vasculature. Here, we demonstrate that local delivery of the soluble, stable, and potent Ang1 variant, COMP-Ang1 gene or protein, into the penises of hypercholesterolemic mice increases cavernous angiogenesis, eNOS phosphorylation, and cGMP expression, resulting in full recovery of erectile function and cavernous blood flow up to 8 weeks after treatment. COMP-Ang1-induced promotion of cavernous angiogenesis and erectile function was abolished in Nos3^-/- mice and in the presence of the NOS inhibitor, L-NAME. COMP-Ang1 also restored the integrity of endothelial cell-cell junction by down-regulating the expression of histone deacetylase 2 in the penis of hypercholesterolemic mice and in primary cultured mouse cavernous endothelial cells. These findings constitute a new paradigm toward curative treatment of both cavernous angiopathy and ED.

Sexual dysfunction in patients with spinal cord lesions

Many aspects of sexuality can be disrupted following a spinal cord lesion (SCL). It can alter an individual's self-esteem and body image, interfere with positioning and mobility, introduce unexpected problems with incontinence and spasticity, decrease pleasure, and delay orgasm. Sexual concerns in men can involve erectile function, essential for intercourse, ejaculation function, necessary for fertility, and the ability to reach orgasm. In women they can involve concerns with vaginal lubrication, genital congestion, and vaginal infections, which can all go unnoticed, and orgasm, which may be lost. All of these concerns must be addressed during rehabilitation as individuals with SCL continue to live an active sexual life, and consider sexuality among their top priority for quality of life. This chapter describes the impact of SCL on various phases of men's and women's sexual responses and on various aspects of sexuality. Treatments are described in terms of what is currently available and what is specific to the SCL population. New approaches in particular for women are described, along with tips from sexual counseling which consider an overall approach, taking into account the primary, secondary, and tertiary consequences of the SCL on the individual's sexuality. Throughout the chapter, attempts are made to integrate neurophysiologic knowledge, findings from the literature on SCL, and clinical experience in sexual rehabilitation.

PDE5 inhibitors as therapeutics for heart disease, diabetes and cancer

The phosphodiesterase 5 (PDE5) inhibitors, including sildenafil (Viagra™), vardenafil (Levitra™), and tadalafil (Cialis™) have been developed for treatment of erectile dysfunction. Moreover, sildenafil and tadalafil are used for the management of pulmonary arterial hypertension in patients. Since our first report showing the cardioprotective effect of sildenafil in 2002, there has been tremendous growth of preclinical and clinical studies on the use of PDE5 inhibitors for cardiovascular diseases and cancer. Numerous animal studies have demonstrated that PDE5 inhibitors have powerful protective effect against myocardial ischemia/reperfusion (I/R) injury, doxorubicin cardiotoxicity, ischemic and diabetic cardiomyopathy, cardiac hypertrophy, Duchenne muscular dystrophy and the improvement of stem cell efficacy for myocardial repair. Mechanistically, PDE5 inhibitors protect the heart against I/R injury through increased expression of nitric oxide synthases, activation of protein kinase G (PKG), PKG-dependent hydrogen sulfide generation, and phosphorylation of glycogen synthase kinase-3β - a master switch immediately proximal to mitochondrial permeability transition pore and the end effector of cardioprotection. In addition, PDE5 inhibitors enhance the sensitivity of certain types of cancer to standard chemotherapeutic drugs, including doxorubicin. Many clinical trials with PDE5 inhibitors have focused on the potential cardiovascular and anti-cancer benefits. Despite mixed results of these clinical trials, there is a continuing strong interest by basic scientists and clinical investigators in exploring their new clinical uses. It is our hope that future new mechanistic investigations and carefully designed clinical trials would help in reaping additional benefits of PDE5 inhibitors for cardiovascular disease and cancer in patients.

Vardenafil dihydrochloride

Vardenafil (VAR) is synthetic, highly selective, and potent inhibitor of phosphodiesterase-5 which competitively inhibits cyclic guanosine monophosphate (cGMP) hydrolysis and thus increases cGMP levels. It is clinically approved for treatment of erectile dysfunction in men, including diabetic and postprostatectomy patients. Several methods of VAR synthesis are included in this review. UV spectroscopy of VAR showed a λmax of approximately 270nm, and IR spectroscopy principal peaks were observed at 3420 (NH), 1724 (CO), 1600 (CC, and CN), 1491 (CHCH) cm(-1). Characteristic carbonyl (CO) carbon was observed in nuclear magnetic resonance spectroscopy at 162.44ppm. The molecular mass was observed at m/z=488.9 (molecular weight=488.2) and the fragmentation pattern was studied using ion trap mass spectrometry. In addition, different analytical methods for determination of vardenafil are also described in this profile. Pharmacokinetic properties of VAR have great impact on efficacy. VAR is rapidly absorbed and slowly metabolized, with an absolute bioavailability of 15%. It is extensively metabolized by CYP3A4 into several metabolites, the most pharmacologically active of which is N-desethyl VAR (M1). The elimination half-life of VAR and M1 is about 4-5h. VAR is primarily excreted as metabolites in the feces and to a small extent in urine. VAR is generally well tolerated, with a favorable safety profile and few transient side effects, including headache, flushing, dyspepsia, and rhinitis.

Nonresponders, partial responders, and complete responders to PDE5 inhibitors therapy according to IIEF criteria: validation of an anchor-based treatment responder classification

INTRODUCTION

Despite widespread use of the International Index of Erectile Function (IIEF) in erectile dysfunction (ED) research, there are no published criteria for classifying ED treatment responders in clinical trials or patient management settings. A new classification for treatment response in men with ED has been developed and validated in a large clinical trial database.

AIM

The study aims to test discriminant and convergent validity of the responder classification and examine the role of covariates.

METHOD

Treatment assignment was used to test discriminant validity. The diary-based Sexual Encounter Profile (SEP) question ("Did your erection last long enough for you to have successful intercourse?") and Global Assessment Question (GAQ) ("Has the treatment you have been taking over the past study interval improved your erections?") were used to evaluate convergent validity. Chi-square and Cochran-Armitage trend tests were used to examine outcome associations. Logistic regression was used to further assess the relationship of outcomes controlling for covariates.

MAIN OUTCOME MEASURE

The classification measure was developed and validated in a database from 17 clinical trials in 3,252 men with ED randomized to placebo or tadalafil. The treatment responder is defined as complete (erectile function [EF] ≥ 26); partial (EF < 26; met minimal clinically important difference [MCID] criteria); or nonresponder following treatment (EF < 26; did not meet MCID).

RESULTS

The new responder definition performed consistently well in all prespecified tests of validity. Eighty-nine percent of subjects classified as complete responders were in the treatment group, and the responder definition was associated with changes on the SEP and GAQ measures, respectively (SEP odds ratio [OR] = 14, 95% confidence intervals [CI] 11-17; GAQ OR = 50, 95% CI 39-88; complete vs. nonresponders).

CONCLUSIONS

We developed and validated a novel method of defining an ED treatment responder based on multiple IIEF criteria and using other measures (SEP, GAQ) for validation. The results have implications for understanding results of clinical trials in ED, and in monitoring response to treatment in the clinic.

High patient satisfaction after inflatable penile prostheses implantation correlates with female partner satisfaction

INTRODUCTION

Patient and female partner satisfaction after implantation of an inflatable penile prosthesis (IPP) assessed by objective means, and the correlation between the partners, is important for determining postoperative sexual life.

AIM

The primary goal was to evaluate patients' erectile function and patients' and their partners' satisfaction after IPP implantation. A secondary aim was to investigate potential determinative factors of satisfaction according to device characteristics, demographics, and cause of erectile dysfunction (ED).

METHODS

Ninety patients, who underwent IPP implantation as an alternative to refractory or undesirable medical treatment for ED, were evaluated. Patients who could not or refused to participate, or were out of a relationship, were excluded. The 69 remaining patients were evaluated for their pre- and postoperative erectile function and posttreatment satisfaction for themselves and their partners.

MAIN OUTCOME MEASURES

Preoperative and postoperative scores on the International Index of Erectile Function Questionnaire-five items (IIEF-5) were compared. The Erectile Dysfunction Inventory of Treatment Satisfaction (EDITS) was given to males and their female partners. Patient demographics, etiology of ED, and implant characteristics were correlated also with patients' EDITS scores.

RESULTS

Mean IIEF-5 scores demonstrated a significant improvement after IPP implantation: from 8.88±3.75 to 20.97±4.37 (P<0.001). The mean patients' EDITS score was 75.48±20.54, whereas mean female partners' score was 70.00±22.92, highlighting high posttreatment satisfaction for both. Regression analysis suggested a direct linear correlation of satisfaction between the sexual partners as a degree of satisfaction. There were no statistically significant differences according to level of education or implant characteristics. Concerning the etiology of ED, no conclusions could be made.

CONCLUSIONS

Overcoming previous limitations in determining post-IPP implantation satisfaction, our study reiterates high rates of patient and partner satisfaction. Of particular note, patient satisfaction appears independent of prosthesis type and cylinder length.

PDE5 inhibitors: considerations for preference and long-term adherence

INTRODUCTION

Erectile dysfunction (ED) is a highly prevalent condition affecting nearly one in five men worldwide. The advent of phosphodiesterase type 5 inhibitors (PDE5i) has revolutionised the ED treatment landscape and provided effective, minimally invasive therapies to restore male sexual function.

MATERIALS AND METHODS

A pubmed search was performed of all English language articles from 1996 to present reviewing PDE5i, including pharmacokinetics, efficacy profiles and comparisons, where available.

RESULTS

Currently available PDE5i in the United States include sildenafil, vardenafil, tadalafil and avanafil, each of which has unique side effect, pharmacokinetic and outcome profiles. Sildenafil is associated with increased rate of visual changes, vardenafil with QT prolongation and tadalafil with lower back pain. Avanafil and vardenafil orodispersible tablet rapidly achieve peak plasma concentration, which results in faster onset of action, whereas tadalafil exhibits the longest half-life. First time response to PDE5i is approximately 60-70%, with no significant differences in efficacy noted among therapies. The literature does not clearly demonstrate a preference for one drug. High-treatment success rates (89%) were reported when patients were prescribed all available PDE5i. Daily dosing with tadalafil is associated with improved erectile function (EF) over time. Finally, novel modes of patient-provider interaction, including internet-based education, communication and prescribing, may also improve long-term adherence.

CONCLUSIONS

PDE5i represent first line therapy for ED with excellent overall efficacy and satisfactory side effect profiles. Enhanced communciation, coupled with increased knowledge of drug characteristics, comparative treatment regimens and optimal prescribing patterns, offer compelling tools to improve long-term treatment success.